Complex.php

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<?php

class Complex {

        private $realPart = 0;
        private $imaginaryPart = 0;
        private $suffix = NULL;

        public static function _parseComplex($complexNumber)
        {
                //      Test for real number, with no imaginary part
                if (is_numeric($complexNumber))
                        return array( $complexNumber, 0, NULL );

                //      Fix silly human errors
                if (strpos($complexNumber,'+-') !== FALSE)
                        $complexNumber = str_replace('+-','-',$complexNumber);
                if (strpos($complexNumber,'++') !== FALSE)
                        $complexNumber = str_replace('++','+',$complexNumber);
                if (strpos($complexNumber,'--') !== FALSE)
                        $complexNumber = str_replace('--','-',$complexNumber);

                //      Basic validation of string, to parse out real and imaginary parts, and any suffix
                $validComplex = preg_match('/^([\-\+]?(\d+\.?\d*|\d*\.?\d+)([Ee][\-\+]?[0-2]?\d{1,3})?)([\-\+]?(\d+\.?\d*|\d*\.?\d+)([Ee][\-\+]?[0-2]?\d{1,3})?)?(([\-\+]?)([ij]?))$/ui',$complexNumber,$complexParts);

                if (!$validComplex) {
                        //      Neither real nor imaginary part, so test to see if we actually have a suffix
                        $validComplex = preg_match('/^([\-\+]?)([ij])$/ui',$complexNumber,$complexParts);
                        if (!$validComplex) {
                                throw new Exception('COMPLEX: Invalid complex number');
                        }
                        //      We have a suffix, so set the real to 0, the imaginary to either 1 or -1 (as defined by the sign)
                        $imaginary = 1;
                        if ($complexParts[1] === '-') {
                                $imaginary = 0 - $imaginary;
                        }
                        return array(0, $imaginary, $complexParts[2]);
                }

                //      If we don't have an imaginary part, identify whether it should be +1 or -1...
                if (($complexParts[4] === '') && ($complexParts[9] !== '')) {
                        if ($complexParts[7] !== $complexParts[9]) {
                                $complexParts[4] = 1;
                                if ($complexParts[8] === '-') {
                                        $complexParts[4] = -1;
                                }
                        //      ... or if we have only the real and no imaginary part (in which case our real should be the imaginary)
                        } else {
                                $complexParts[4] = $complexParts[1];
                                $complexParts[1] = 0;
                        }
                }

                //      Return real and imaginary parts and suffix as an array, and set a default suffix if user input lazily
                return array( $complexParts[1],
                                          $complexParts[4],
                                          !empty($complexParts[9]) ? $complexParts[9] : 'i'
                                        );
        }       //      function _parseComplex()


        public function __construct($realPart, $imaginaryPart = null, $suffix = 'i')
        {
                if ($imaginaryPart === null) {
                        if (is_array($realPart)) {
                                //      We have an array of (potentially) real and imaginary parts, and any suffix
                                list ($realPart, $imaginaryPart, $suffix) = array_values($realPart) + array(0.0, 0.0, 'i');
                        } elseif((is_string($realPart)) || (is_numeric($realPart))) {
                                //      We've been given a string to parse to extract the real and imaginary parts, and any suffix
                                list ($realPart, $imaginaryPart, $suffix) = self::_parseComplex($realPart);
                        }
                }

                //      Set parsed values in our properties
                $this->realPart = (float) $realPart;
                $this->imaginaryPart = (float) $imaginaryPart;
                $this->suffix = strtolower($suffix);
        }

        public function getReal()
        {
                return $this->realPart;
        }

        public function getImaginary()
        {
                return $this->imaginaryPart;
        }

        public function getSuffix()
        {
                return $this->suffix;
        }

        public function __toString() {
                $str = "";
                if ($this->imaginaryPart != 0.0) {
                        if (abs($this->imaginaryPart) != 1.0) {
                                $str .= $this->imaginaryPart . $this->suffix;
                        } else {
                                $str .= (($this->imaginaryPart < 0.0) ? '-' : ''). $this->suffix;
                        }
                }
                if ($this->realPart != 0.0) {
                        if (($str) && ($this->imaginaryPart > 0.0))
                                $str = "+" . $str;
                        $str = $this->realPart . $str;
                }
                if (!$str)
                        $str = "0.0";
                return $str;
        }

}